Gums in Sausage Manufacturing
Gelatin and starch are two known gums that are used in sausages. Gelatin is used in head cheeses and meat jellies and potato starch has been often added to Russian sausages. Traditionally made sausages can be made without any gums as long as proper meat cuts are selected for particular sausages, for example if pork cuts with a lot of connective tissue are slow cooked in a little water, enough natural gelatin will be produced to produce a good textured head cheese. Ground meat should have enough binding power to bind meats together in a regular sausage.
The difficulty arises when we decide to re-invent the typical sausage composition by eliminating fat and introducing filler material such as rice, flour, rusk, bread crumbs, oats, barley or buckwheat groats, semolina flour, textured vegetable protein (TVP) potatoes or beans. Such fillers can be added to many sausages to make them healthier. The fillers by lower calories and cholesterol and extend the value of the sausage. Vegetarian sausages do not employ meats at all, however, the ingredients must be bound together the same. We can use traditional solutions that call for soy proteins, egg white, gelatin, flour, starch or non-fat dry milk, but why not to use gums? After all this is what the food industry is using.
Gums, technically referred to as hydrocolloids, originate from different sources. They can immobilize water and contribute viscosity. If you look at processed food, you see all sorts of other gums like carrageenan, xanthan gum, cellulose gum, locust bean gum, gum arabic, agar, and so on. The value of gums is not as a fat replacer but as a thickener which can combine with water and create gel. Gums fulfill several functions in food products:
- 1. They thicken things - ice cream, syrups.
- 2. They emulsify things - mixed liquids stay together without separating.
- 3. They change the texture - a gum will make something thicker.
- 4. They stabilize crystals - a gum might help prevent sugar or ice from crystallizing.
- 5. They help to reduce cooking loss which results in a higher yield and more succulent product.
The most popular gums:
- Gellan Gum
- Gum Arabic
- Guar Gum
- Locust Bean Gum
- Konjac Gum
- Xantham Gum
While at first glimpse, such exotic names may discourage consumers from ever considering such products, the truth is that they are natural products which we consume all the time. The are added to ice creams, puddings, sauces and processed foods that require a creamy texture. Without gums sugar crystals will separate from ice cream and many products would turn into a watery mess.
We take for granted that manufactured foods should always look good and taste well, but there is more to that than meets the eye. Food products are made in one location, then stored in a different one, and then transported many miles to a supermarket where they will sit on a shelf for some time. Gums hold those products together. The reason that we dedicate so much space to gums is that they become more popular every day. Originally, only food technologists understood the subject and they were the ones to add them into food products. Today gums are commonly available and used in general cooking. For example traditional jams were made by stirring the mixture of fruit and sugar for hours until it lost enough moisture to gel. Pectin shortens the process to minutes and the product looks better and has a better consistency.
Let’s make something clear-an occasional cook or a sausage maker does not need to use things like carrageenan, Konjac flour or xanthan gum to give the sausage a superior texture. Commercial producers need to use gums, as their products, for example thinly sliced packaged ham, must hold its shape for a long time. A hobbyist can also use less expensive agents like gelatin, flour, eggs or protein concentrate, because the time between making the product and consumption is usually very short. Nevertheless, the information presented here, will enable the reader to have a better understanding of the subject and will make it easier to further expand his knowledge by reading more technical books.
Agar is made from the same family of red seaweeds as carrageenan. Agar is a natural vegetable gelatin counterpart. White and semi-translucent, it is sold in packages as washed and dried strips or in powdered form. Agar is approximately 80% fiber and is a very popular product in Asia. It can be used as an addition or as a replacement to pectin in jams and marmalades, as a substitute to gelatin for its superior gelling properties, and as a strengthening ingredient in souffles and custards. Agar is rather expensive.
Alginic acid, also called algin or alginate, is an anionic polysaccharide distributed widely in the cell walls of brown algae, where it, through binding water, forms a viscous gum. In extracted form it absorbs water quickly; it is capable of absorbing 200-300 times its own weight in water. The chemical compound sodium alginate is the sodium salt of alginic acid. Sodium alginate is a flavorless gum, used to increase viscosity and to act as an emulsifier.
Carrageenan is a natural extract from red seaweeds used in processed foods for stabilization, thickening, and gelation. During the heating process carrageenan can absorb plenty of water and trap it inside. This results in a higher cooking yield and less purge during storage. About 0.01% (1 g per kg of meat) can increase the yield of the finished product up to 8%. Usually, up to 1.0% (10 g/kg) of carrageenan is added to processed meats. Carrageenan does not disperse easily in cold water, but will create a gel when the liquid is heated. It forms a solid gel during cooling. Carrageenan improves sliceability of processed meats. The sausages with added carrageenan are firmer and the casing peels off much easier. Be aware that adding more than 0.5% carrageenan may result in a tough gummy texture. Many vegetarians use carrageenan instead of gelatin, since carrageenan is 100% vegetarian and gelatin is made from pork skins.
There are three types of carrageenan employed in the food industry:
- Kappa - meat products, very strong gel. It is currently the most used type of carrageenan in low fat sausages.
- Iota - meat products, medium strong gel.
- Lambda - sauces and dressings. Does not gel.
Kappa carrageenan gels better in the presence of alkali agents such as potassium chloride (KCL). Enough potassium chloride is usually added to the carrageenan blend to create a strong gel. Potassium chloride is the same salt that is added to Morton’s Low Salt, at 50% level, thus the salt itself promotes the development of strong gel. In addition milk protein is a strong promoter of carrageenan gels. Adding caseinate (milk protein) or non-fat dry milk will assist in the development of strong carrageenan gel. Kappa and Iota carrageenan are only partially cold water soluble and need to be heated for full activation. Lambda carrageenan is fully cold water soluble.
It is the gum of choice for making brine solutions that are pumped into whole meats. It binds water well and improves sliceability of processed meats.
Gellan gum is a high molecular weight polysaccharide (i.e., complex sugar) gum produced as a fermentation product by a pure culture of the microbe Sphingomonas elodea. Gellan gum is a food additive that acts as a thickening or gelling agent, and can produce gel textures in food products ranging from hard and brittle to fluid. Gellan is used in bakery fillings, confections, dairy products, dessert gels, frostings, glazes, jams and jellies, low-fat spreads, and other products.
Gum arabic is the hardened sap of the Acacia senegal tree, which is found in the swath of arid lands extending from Senegal on the west coast of Africa all the way to Pakistan and India. It’s a natural emulsifier, which means that it can keep together substances which normally would not mix well. Pharmaceutical companies use it to keep medicines from separating into their different ingredients, and a dab of gum arabic makes newspaper ink more cohesive and permanent. Coca-Cola uses gum arabic to keep the sugar from precipitating to the bottom of its sodas. Gum arabic is tasteless and edible. As a food additive, it has been extensively tested and is considered to be one of the safest additives for human consumption.
Gum arabic has many non-food uses as well. It is used in paints, inks, glues, printing, cosmetics, photography, incense cones, shoe polish, postage stamps, cigarette paper adhesive, and pyrotechnic operations. In beverages, gum arabic helps citrus and other oil-based flavors remain evenly suspended in water. Gum arabic can be completely dissolved in its own volume of water. In confectionery, glazes and artificial whipped creams, gum arabic keeps flavor oils and fats uniformly distributed, retards crystallization of sugar, thickens chewing gums and jellies, and gives soft candies a desirable mouth feel. In cough drops and lozenges, gum arabic soothes irritated mucous membranes. Many dry-packaged products, such as instant drinks, dessert mixes and soup bases, use it to enhance the shelf life of flavors. The gum is used in soft drink syrups, chocolate candies, gummy candies, and marshmallows. Like gelatin and carrageenan, gum arabic can be used to bind food substances as well as to smoothen textures, or to hold flavoring.
Guar gum is made from the seeds of a plant that grows in India and Pakistan. When placed in contact with water, guar gum will gel even at low concentrations (1% to 2%). Guar gum has been used for centuries as a thickening agent for foods and pharmaceuticals.
Locust Bean Gum
Locust bean gum, also known as carob gum, carob bean gum, and carobin is a galactomannan vegetable gum extracted from the seeds of the Carob tree, mostly found in the Mediterranean. The taste of locust bean powder is similar to ground cocoa powder, but it contains less fat and calories than cocoa. It is dispersible in either hot or cold water. Locust bean gum is used in food products, cosmetics and other products.
Note: guar gum and locust bean gum belong to a group of gums that are known as Galactomannans.
Both gums are excellent thickeners and are added to low fat products to bind water. They are used in sausages to soften the texture and to facilitate stuffing. The clear advantage of both gums is that they can hold water at high temperatures, for example during the baking process, which results in a better product.
Konjac flour also called konjac gum or konjac glucomannan is produced from the konjac plant root and can form meltable or heat stable gels. Konjac flour is rich in soluble fiber, but does not contain starch or sugar so it does not have calories. It is also gluten free. Its thickening power is 10 times greater than cornstarch. Konjac has the highest water holding capacity of any soluble fiber-up to 100 times its own water weight. One part of glucomannan can absorb 50 parts of liquid. About one teaspoon of konjac flour can gel about one cup of liquid, which may be water, meat stock or wine. Konjac powder can be used as a thickener for smooth gravies, sauces, glazes, soups, stews and casseroles. Konjac interacts synergistically with carrageenan, xanthan gum, locust bean gum. Konjac interacts with most starches increasing viscosity and allowing improvement of texture. As a gelling agent, konjac exhibits the unique ability to form thermo-reversible and thermo-irreversible gels under different conditions:
- Reversible gum- konjac mixed with xanthan gum.
- Non-reversible gum-when konjac heated at a pH of 9-10 (alkali added).
With addition of a mild alkali such as calcium hydroxide, Konjac will set to a strong, elastic and thermo-irreversible gel. This gel will remain stable even when heated to 212° F (100° C) and above. Konjac will form a reversible gel when it is mixed with xanthan gum. Due to the thermo-irreversible property of the konjac gum, it has become popular to make a great variety of foods such as konjac cake, konjac noodles, and foods for vegetarians.
Preparing Konjac Gel
If konjac flour is added directly to food it may create lumps. Konjac powder thickens slowly when mixed with cold water, but quickly thickens when it’s heated. Mix konjac flour with cold water or other liquid first, stirring often until fully dissolved. Then add konjac flour to a hot liquid or food that is cooking. It has no taste of its own so it inherits the flavor of the product. Konjac flour can be mixed with other gums or starches. If you have not used konjac powder as a thickening agent before, it is best to experiment with it by beginning with lesser amounts, and adding as necessary until the desired consistency is reached. The addition of 0.02-0.03% konjac to 1% xanthan gum will raise its viscosity by 2-3 times under heating. Konjac is usually added at 0.25-0.50%.
Konjac flour works like magic. Take 1 g of konjac, add 100 g of water, stir and within seconds a gel is formed. Unlike gelatin, carrageenan or starch, konjac does not need to be heated in order to gel. It is transparent and almost feels like fat. A good starting point is to mix 1 g of konjac with 1/2 cup (120 g) of water. Add the mixture into the ground meat, mix with spices and you get a much better non-fat sausage. Konjac reacts synergistically with starches which makes such a combination especially useful for making reduced-fat products.
Konjac is used by people trying to lose weight as it provides the feeling of fullness. One teaspoon of konjac is mixed with 8 ounces of liquid and is drunk immediately as it will gel. For those reasons konjac gum should not be swallowed on its own, as it may draw saliva and moisture in our food tract, create gel and stoppage. It is safe when taken with large amounts of water. People on diets take konjac drinks three times a day.
Konjac flour is water hungry and will bind all available free water for forming gel. The texture will be fine but hard. Adding 10-15% water to ground meat will create a better product. Even more water can be added when making emulsified sausages in a food processor.
Xanthan gum is produced by fermentation of glucose, sucrose (corn sugar), or lactose by bacteria. During fermentation, a strain of bacteria (Xanthomonas campestris) turns sugar into a colorless slime called xanthan gum. Xanthan gum is most often found in salad dressings and sauces. It helps to prevent oil separation by stabilizing the emulsion, although it is not an emulsifier. Xanthan gum also helps suspend solid particles, such as spices. Also used in frozen foods and beverages, xanthan gum helps create the pleasant texture in many ice creams, along with guar gum and locust bean gum Xanthan gum is soluble in cold water but in order to eliminate lumps, it should be well agitated.
Xanthan gum does not gelatinize when used alone, but it can form gel at any pH when used with konjac gum. At a ratio of 3 (xanthan) : 2 (konjac) the strongest gel is obtained. The gel is thermo-reversible: it is in solid state at temperatures below 40° C (104° F), but it will be in a semi-solid or liquid state at temperatures of 50° C (122° F) or above. When the temperature drops back to the ambient temperature <40° C (<122° F), it will resume the solid state.
Preparing Xanthan Gel
Xanthan gum does not gel by itself but a combination of 2 parts of konjac with 3 parts of xanthan creates a very strong gel. One gram of konjac plus 1.5 grams of xanthan will gel within seconds in one cup of water (236 g). Xanthan gum does not need to be heated, it gels with cold liquid. Xanthan can be mixed with an equal amount of guar gum which is less expensive.
It is often desirable to use a combination of gums to create a synergistic effect. Synergy means that a combined effect of two or more ingredients is greater than it would be expected from the additive combination of each ingredient. In this case the viscosity or gel strength will be greater if the following combinations are created:
- Xantham gum with guar gum.
- Xantham gum with bean gum.
- Konjac with carrageenan.
- Konjac with xanthan.
The above combinations may be used at a one-to-one ratio with each other.
The synergistic effect is also present when a gum is combined with starch.
- Konjac with starch.
- Carrageenan with starch.
Adding modified starch and gum to food produces a similar effect. However, modified starch is less expensive than a gum. Adding starch to ground meat is a universally accepted method. On the other hand 1 part of gum will produce a similar effect as 10 parts of starch, so the result balances out. Using gum is more crucial in fine products like yoghurt or pie filling where the change in flavor and mouthfeel is easy to notice.
Synergistic results of combining different gums are based on liquid gels. Those combinations may behave differently when added to ground meat. They will definitely bind water and create gels, but they may exhibit a weaker synergistic effect. The gums most often used in processed meats are: carrageenan, xanthan and konjac.